Method and Device for Addressing Leg Length Inequality

ABSTRACT

A heel lift assembly is provided for use in a variety of types of footwear including open toed and open heeled footwear. Such a heel lift assembly comprises a plurality of assorted removable and interchangeable heel lifts which may be worn alone or used together with an insole and outsole combination which are part of an open toed and/or open heeled shoe assembly. The plurality of interchangeable and removable heel lifts are connected to each other by an assembly using grooves on the bottom of each heel lift and one or more attachment points on the upper surface of the each subsequent heel lift.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent Application No. 61/937,668 filed Feb. 10, 2014, the contents of which are herein incorporated by reference in their entirety.

BACKGROUND

Leg length inequality can be divided into two categories: functional inequality, in which the legs are actually the same length but some other inequality such as pelvic obliquity creates the appearance of leg length inequality, and actual inequality in which there is an anatomical difference in the length of the legs. Between 40 to 70% of the general population has an inequality of 5 mm or more (Knutson, Gary A. “Anatomic and Functional Leg-Length Inequality: A Review and Recommendation for Clinical Decision-Making. Part I, Anatomic Leg-Length Inequality: Prevalence, Magnitude, Effects and Clinical Significance.” Chiropractic & Osteopathy 13 (2005)) and approximately 1 in 1,000 people use a corrective device. (Guichet J M, Spivak J M, Trouilloud P, et al: Lower limb-length discrepancy. an epidemiologic study. Clin Orthop 272:235-241, 1991).

The spine, pelvis and lower extremities compensate for leg length asymmetry by shifting the center of gravity. Common compensations include coronal pelvic tilt, lumbar scoliosis, knee flexion, genu recuvatum, subtalar joint pronation, ankle plantar flexion and foot supination. These compensations can cause backache, pain, premature degenerative arthritis, flank pain, arthritis, psoasitis, arthritis of the hip, patellar tendinitis, patellofemoral pain syndrome, plantar fasciitis, medial tibial stress syndrome, metarsalgia illotibial band syndrome with knee pain, trochanteric bursitis, sacroiliac discomfort, Achilles tendinitis and cuboid syndrome. Additionally, physical compensation for leg length inequality can lead to further orthopedic complications such as degenerative arthritis, full spinal scoliosis, and/or lower back pain.

While technology exists to address leg length discrepancy, there are problems with patient compliance frequently due to discomfort, fitting limitations, and appearance of the heel lift. Additionally, conventional heel lifts have problems with slippage or inflexibility during the “toe off” part of the gait cycle. Traditional heel lifts are designed to only fit a narrow selection of shoes, namely lace up shoes, loafers, or other flat shoes with quarters and counters and not the wide variety of shoes currently on the market. Given the problems with patient compliance and the inability to use traditional heel lifts with a wide variety of shoes, there is a need for alternate heel lifts.

BRIEF SUMMARY

Disclosed is a variable removable heel lift assembly for use alone or in combination with a sandal designed to incorporate the variable removable heel lift. Such a heel lift may be used to correct both functional and actual leg length inequality, both of which shift the center of gravity causing further orthopedic complications.

Leg length inequality may be measured by any means generally used including clinical and radiographic means. Once the difference in the leg lengths is determined, an individual may be fitted with a heel lift of sufficient height to compensate for the difference in the leg lengths resulting in a right and left leg of substantially equal length.

The variable removable heel lift assembly described here comprises a series of one or more heel lifts that may be placed above or underneath an insole. In some embodiments, the insole may include a thickened heel portion which forms part of the variable removable heel lift assembly. The heel lifts that make up the variable removable heel lift assembly may be the same or different heights, thicknesses, and/or materials and may have the same or different surfaces. In some embodiments, the uppermost heel lift may have a substantially flat first surface and a divided recessed second surface. Subsequent heel lifts may have a series of protrusion connection points that fit into the divided recessed second surface of the heel lift above. Such protrusion connection points may be designed to hold the individual heel lifts together to form the variable removable heel lift assembly. In some embodiments, the first heel lift may also have a series of protrusion connection points. Such protrusion connection points may additionally have therapeutic benefits such as massage, pressure or acupressure points. In some embodiments, the upper surface of the heel lifts may be substantially smooth or may be textured to create a non-slip or fashionable surface. In some embodiments, an additional material may be affixed to the raised portion of the divided recessed second surface to provide additional aid in keeping the variable removable heel lift assembly in place in a shoe.

Each heel lift in the variable removable heel lift assembly may be the same or different heights which together correct the leg length inequality in an individual. In some embodiments, the uppermost heel lift in the variable removable heel lift assembly may be thinner than subsequent heel lifts. Heel lift thicknesses may range from 1 mm to 12 mm at the thickest point including heel heights of 3 mm, 5 mm, 7 mm, 9 mm and 12 mm. The slope of the variable removable heel lift assembly may be no greater than 5.5 degrees. In some embodiments, the slope of the variable removable heel lift assembly may be between about 0.5 to about 5.5 degrees. In other embodiments, the uppermost heel lift may be softer and/or more compressible than subsequent heel lifts in the heel lift assembly. In some embodiments the uppermost heel lift may include a heel cup.

The variable removable heel lift assembly may be used in any type of shoe desired. In some embodiments, it may be part of shoe designed to contain the variable removable heel lift assembly. Such a shoe may include an outsole with a recessed inner opening, an insole with a series of depressions along the bottom, an upper which wraps around the outer edge of the insole, and the variable removable heel lift assembly below the insole, held in place and hidden by the raised heel of the outsole. Additional features and advantages will be better understood in view of the detailed description provided below.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

FIG. 1 is a top view of an embodiment of a heel lift.

FIG. 2 is an exploded view of an embodiment of a heel lift assembly.

FIG. 3 is a top view of an embodiment of a heel lift.

FIG. 4 is a bottom view of an embodiment of a heel lift.

FIG. 5 is an embodiment of a heel lift attachment point.

FIG. 6 is a rear view of an embodiment of a heel lift assembly.

FIG. 7 is a top view of an outsole.

FIG. 8 is a side view of an embodiment of an outsole.

FIG. 9 is a rearview of an embodiment of an outsole.

FIG. 10 is a bottom view of an embodiment of an insole.

FIG. 11 is a top view of an embodiment of an insole.

FIG. 12 is a side view of an embodiment of an insole.

FIG. 13 is an exploded view of an embodiment of a slide style shoe.

FIG. 14 is a top view of an embodiment of an assembled slide style shoe.

FIGS. 15 A and B are sectional views of an embodiment of a slide shoe without (A) and with (B) a heel lift assembly.

DETAILED DESCRIPTION

Leg length inequality affects up to 70% of the population. Legs may be slightly different lengths because of genetics, infection, surgical interventions (knee replacements, hip replacements) or accidents. For many people a slight inequality, usually less than 5 mm, does not cause any noticeable problems. However, for those with a larger inequality, leg asymmetry can change a person's gait and alter the forces acting on the body as an individual walks or runs, increasing the risk of osteoarthritis in the knee and hip, generating low back pain, and creating stress fractures. In addition, functional scoliosis, posture deformation and discopathy may occur, causing postural issues throughout the spine.

Leg length inequality may be determined using any method known to those of skill in the art. For example, a tape measure may be used to measure the length of each lower extremity by measuring the distance between the anterior superior iliac spine (ASIS) and the medial malleolus. In another embodiment, the pelvis of the erect patient may be leveled by placing blocks of known height under the short limb and varying the heights of the block until the pelvis is level. In a further embodiment, leg length inequality may be determined using standard radiography including orthoroentogenogram, scanogram, and teleoroentgenogram. In yet another embodiment, computed radiography, ultrasound, CT scanogram, MRI scan, or microdose digital radiography may be used to determine the difference in leg lengths in an individual. Once the difference in leg lengths in an individual is determined, a heel lift height may be chosen that is approximately equal to the difference in leg lengths.

Standard heel lifts are 3 mm, 5 mm, 7 mm, 9 mm, and 12 mm with the possibility of other incremental sizes from 1 mm to 12 mm. To be effective, heel lifts should be worn at all times, however, due to difficulties in fitting standard heel lifts into a variety of shoe types, most patients do not wear their heel lifts as prescribed, resulting in back, hip, knee or other pain and degenerative wear. Described herein is a variable removable heel lift assembly that can be worn in a variety of types of shoes including, but not limited to, shoes without counters, corners, or toe boxes such as flip-flops, slides, mules, or other sandals. The variable removable heel lift assembly may additionally be worn with more traditional shoes including, but not limited to, loafers, clogs, boots, athletic shoes, flats, brogues, oxfords, derbys, heels and the like. Such heel lift assemblies may have variable widths as well as variable heights, increasing their suitability for different types of shoes and increasing the comfort of individual users.

With reference to FIG. 1, a heel lift 104 has a first surface 106, a bottom or second surface 108 and a height 102, with the maximum height at the rear portion of the heel lift and the height decreasing to form a slope towards the front of the heel lift 110. The slope of the heel lift may vary between about 0.1 and about 5.5 degrees, between about 0.5 and about 5.3 degrees, about 0.25 and about 5 degrees, or any variation thereof. In some embodiments, the heel lift may be associated with one or more additional heel lifts in order to create the desired heel height. In further embodiments, the heel lift 104 is shaped to form a heel cup with a raised back and sides. In other embodiments, the heel lift 104 has a substantially flat first surface 106 as shown in FIG. 1. In some embodiments, the top or first surface 106 of the heel lift 104 is smooth. In other embodiments, the first surface 106 of the heel lift 104 is textured. Such textures may be used for non-slip purposes, fashion and comfort. In additional embodiments, the first surface 106 may include a heel cup (not shown).

As shown in FIG. 2, a heel lift assembly 202 comprises a first heel lift 104, with one or more additional heel lifts as exemplified by 206 and 208 (progressively numbered and herein referred to as the second and third heel lift though there may be additional heel lifts as well) with the maximum height at the rear portion of the heel lift assembly and the height gradually decreasing to form a slope towards the front of the heel lift assembly. The slope of the heel lift assembly may vary between about 0.1 and about 5.5 degrees, between about 0.5 and about 5.3 degrees, about 0.25 and about 5 degrees, or any variation thereof.

There may be one, two, three, four, five, six, seven, eight, or more heel lifts in the heel lift assembly. The heel lifts exemplified at 104, 206 and 208 may be used at any time in any order as required by the amount of individual's leg inequality and/or lumbosacral leveling. In some embodiments, the first heel lift 104 is generally found in contact with the sole of the foot of the individual with additional heel lifts such as 206 and 208 placed below the first heel lift 104. In other embodiments, alternate heel lifts such as heel lifts 206 and 208 may be placed in contact with the sole of the foot of the individual wearing the heel lift. In some embodiments the heel lifts may have protrusion connection points 210 which serve to connect a heel lift with the heel lift above. In some embodiments, the protrusion connection points 210 may be shaped so as to provide a massage, therapeutic pressure points, acupressure points and the like or other therapeutic benefits to the sole of the foot of the individual wearing the heel lift assembly. In some embodiments, an individual may start with a single heel lift and progressively increase the thickness and/or number of heel lifts used at a time to allow the individual to become accustomed to wearing the heel lift assembly. In additional embodiments, individual heel lifts may be replaced due to wear without requiring replacement of the entire heel lift assembly.

Heel lifts may be made of any material generally used, including, but not limited to cork, plastic, ethylene vinyl acetate, polyurethane foam, poron, polyurethane elastomers, single density polyurethane, polyether systems, and the like. In some embodiment, hardness is classified as medium to hard grade. Each heel lift in the heel lift assembly may be made of the same or different materials and have the same or different levels of hardness. In some embodiments, the heel lift in contact with the sole of the foot is softer and/or more flexible than a heel lift which is not in contact with the sole of the foot. In other embodiments, the heel lift in contact with the sole of the foot is harder and/or less flexible than a heel lift which is in contact with the sole of the foot. In further embodiments, the heel lift in contact with the sole of the foot may be the same hardness as other heel lifts in the heel lift assembly. The heel lifts may be the same or different heights. In some embodiments, the topmost heel lift is thinner, and/or has less heel height than other heel lifts in the heel lift assembly. In further embodiments, the topmost heel lift may be more compressible than other heel lifts in the heel lift assembly.

In reference to FIG. 3, a first surface of exemplary second heel lift 206 may have one or more protrusion connection points 210, 304, and 308 on a second heel first surface 310. The protrusion connection points may be of any shape that is useful. In some embodiments, the protrusion connection points 210, 304, and 308 may be shaped so as to provide a massage, therapeutic pressure points, acupressure points and the like or other therapeutic benefits to the sole of the foot of the individual wearing the heel lift. In other embodiments, the protrusion connection points 210, 304 and 308 may be any size or shape that allows the heel lifts to connect to each other and/or a shoe insole. For example, it may be a hook, snap, clip, bayonet clip, ball, adhesive, velcro fasteners, rivets, sculpted foam, shaped plastic, shaped EVA, shaped polyurethane, shaped rubber, shaped polyether systems, hook and loop tape, and socket joint, and the like. In some embodiments, the protrusion connection points may fit into the bottom of the heel lift above using a snap fit, friction fit, press fit or interference fit or the like. In additional embodiments the protrusion connection points may provide both a connection point and therapeutic benefits.

The heel lifts described herein may have a second or bottom surface. As shown in FIG. 4, a heel lift 104 may have a second or bottom surface 412. Such a second or bottom surface 412 may be on the second surface of some or all of the heel lifts in the heel lift assembly. In some embodiments, the bottom surface has a separation notch 408 which allows a plurality of heel lifts in an assembly of heel lifts to be separated from each other and from an outsole. The separation notch may be any shape generally desired. In some embodiments, it may be a half circle, a square, a rectangle, a trapezoid and the like.

In some embodiments, the bottom surface 412 has a divider 406. The divider 406 may divide recessed area 410 to create a divided recessed area. Divider 406 may consist of one or more straight and/or curved features, dividing the recessed area 410 into two or more spaces. Protrusion connection points 210, 304 and 308 in the first surface of a heel lift may be shaped to fit securely in the recessed areas 410 using any means of attachment generally used. The protrusion connection points 210, 304 and 308 may be any shape that allows them to fit in the recessed areas 410 including, but not limited to, circular, triangular, pie shaped, sector shaped, trapezoidal, rectangular and the like. In some embodiments, the protrusion connection points of a first heel lift may fit into the bottom of the second heel lift above using a snap fit, friction fit, press fit or interference fit and the like. In some embodiments, an adhesive, hook tape, non-slip tape, textured surface or other substance may be applied to the bottom divider 406 in the heel assembly such that the heel lift assembly sits securely in a shoe. In some embodiments, such substances may be applied to the bottom divider 406 of every heel lift in a heel lift assembly. In other embodiments, such substances may be applied only to the second surface of the heel lift in contact with the shoe.

In some embodiments, as shown in FIG. 5, a first heel lift 502 may attach to a second heel lift 504 by fitting a protrusion connection point 506 with an opening or recessed area 508. The protrusion connection points and corresponding openings may be any shape and number desired to ensure that the heel lifts comprising the heel assembly attach securely to one another including, but not limited circular, triangular, pie shaped, sector shaped, trapezoidal, rectangular and the like. In some embodiments, the opening or recessed area 508 may be the direct inverse of the protrusion connection point 506 or may be part of a larger opening or recessed area as shown at 410. The protrusion connection point 506 may fit into the bottom of the heel lift above using a snap fit, friction fit, press fit or interference fit and the like.

As shown in FIG. 6, a first heel lift 602 is stacked with a second heel lift 604 and a bottom heel lift 606. The series of heel lifts are assembled to form a heel lift assembly. One or more heel lifts 602, 604 and 606 may have a separation notch 608, 610 and 612 respectively. The separation notch 608, 610 and 612 respectively allow each heel lift to be separated from another heel lift or a shoe to allow the user to adjust the height of the heel lift assembly, remove, or replace the heel lift assembly as necessary.

A heel lift and/or heel lift assembly as described herein may be used on its own or may be incorporated into a shoe including shoes without counters, corners, or toe boxes such as flip-flops, mules, or other sandals. For example, as shown in FIG. 7, an outsole 704 may have a first depression 702 designed to incorporate an insole and heel lift. In some embodiments, the depression 702 is surrounded by a lip 718 allowing an insole to be firmly held in place. In some embodiments, the outsole may have a separation notch 708 to allow the removal of the insole and/or heel lift assembly. The outsole 704 may have additional depressions 706, 710, 712, 714, 716 which allow an upper (not shown) to wrap smoothly around the side of an insole and fit in the outsole. As shown in FIG. 8, the outsole 704 may have an angled heel 804 to cover the outer edge of the insole and heel lift assembly. A heel lift assembly and/or insole may be easily removed and replaced using the access zone 708 as shown in FIG. 9.

With reference to FIG. 10, a footbed 1002 for a sandal type shoe is shown. The footbed 1002 has a bottom or second surface 1012. In some embodiments, the footbed 1002 may include one or more depressions such as those shown at 1010. These depressions are equivalent to the thickness of an upper, allowing the upper to lie flatly against the bottom of the shoe. In some embodiments, the depressions 1010 may be the same depth and/or width. In other embodiments, the depressions may be different depths and/or widths. In additional embodiments one or more of the depressions may be the same depth and/or width. Some or all of the depressions may be used with any particular upper. In some embodiments, the footbed 1002 has footbed depression areas 1008 which allow an upper to wrap around the outside of the footbed 1002 and fasten at footbed attachment points along the side of the footbed alone or in addition to attaching to attachment points 1004 in depressions 1010. In some embodiments, the footbed 1002 may have a slit 1006 for the attachment of a strap. As can be seen on footbed 1002, there are a plurality of depressions 1010, footbed depression points 1008, and footbed attachment points 1004 allowing for a variety of uppers and straps to be used with the same footbed. Some or all of the depressions, footbed depression points and footbed attachment points may be used to fasten an upper or strap to the base of the footbed. Footbed attachment point 1004 may be any size or shape that allows the upper or strap to connect to the insole. For example, it may be a hook, snap, clip, bayonet clip, ball and socket joint, ball, pin, and the like. In some embodiments the bottom surface 1012 of the footbed 1002 has a divided recessed area 1020 separated by a divider 1014 and bounded by a raised lip 1016. Such divided recessed area 1020 is shaped such that it can accommodate protrusion connection points on a subsequent heel lift in a heel lift assembly. In addition, in some embodiments, the heel lift may include a central flex point 1018.

As shown in FIG. 11, the footbed 1002 has an upper surface 1104 which may be textured or smooth. In some embodiments, the upper surface 1104 may have a heel cup. The footbed depression areas 1110 are equivalent to the thickness of an upper (not shown), allowing the upper to lie flatly against the side of the shoe when placed in an outsole. In some embodiments, the depressions 1110 may be the same depth and/or width. In other embodiments, the depressions may be different depths and/or widths. A side view of the footbed 1002 is shown in FIG. 12, with the depressions 1110 shown as well as side attachment points 1202 and 1206. Side attachment points 1202 and 1206 may be any size or shape that allows the upper or strap to connect to the insole. For example, it may be a hook, snap, clip, hook and loop tape, bayonet clip, ball and socket joint, and the like. In some embodiments the attachment may be permanent. In other embodiments, the attachment may be interchangeable, allowing a variety of uppers to be used with the same insole and outsole.

An exploded view of an embodiment of a slide style shoe is shown at FIG. 13. The slide style shoe comprises an upper 1302 with upper attachment points 1312 which connect with footbed 1002 attachment points 1202. The insole 1002 attached to the upper 1302, sits in the outsole 704 which has a lip 718 to hold the footbed 1002 in place. A heel lift assembly under the insole would be hidden by the angled heel 804 of the outsole 704.

In the assembled view in FIG. 14, the upper 1302 is attached to the insole 1002 though not all outsole depression areas 706 are used. The upper 1302 and insole 1002 combination is inserted into the outsole 1402. The access zone 708 may be used to remove and insert the footbed 1002. It may be desirable to remove and re-insert the footbed 1002 in order to change the upper 1302 for a different style of upper and/or to insert or modify a heel lift assembly placed under the insole 1002.

A side view of a slide style shoe with (FIG. 15A) and without (FIG. 15B) a heel lift assembly is shown in FIG. 15. The upper 1504 is attached to an insole 1502 at footbed depression and attachment points 1506. The insole 1502 and upper 1504 is then inserted into the outsole 1516. The angled heel 1508 of the outsole 1516 hides the insole which is surrounded on all outer edges by the outsole 1506.

In alternate embodiments as shown in FIG. 15 B, a heel lift or heel lift assembly 1510 may be inserted under the insole 1502 to address issues of leg length inequality. The insertion of the heel lift or heel lift assembly is such that the insole 1502 remains below the edge of the outsole 1516, beneath the outsole lip 1514. The upper 1504 wraps around the insole 1502 at footbed depression 1518 and attachment points 1520 and so that the upper 1504 fits snugly between the outsole depressed areas and fastens in place using attachment points 1520.

Although the invention has been described by reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. It is therefore intended to include within this patent all such changes and modifications as may reasonably and properly be included within the scope of the present invention's contribution to the art. 

What is claimed is:
 1. A heel lift assembly comprising: a first heel lift with a substantially flat first heel lift first surface and a divided recessed first heel lift second surface; a second heel lift with a series of protrusion connection points on a second heel lift first surface and a divided recessed second heel lift second surface; and wherein the series of protrusion connection points of the second heel lift fit into the divided recessed first heel lift second surface to form the heel lift assembly.
 2. The heel lift assembly of claim 1, wherein the substantially flat first heel lift first surface is textured.
 3. The heel lift assembly of claim 2, wherein the texture is a non-slip texture.
 4. The heel lift assembly of claim 1, wherein a piece of hook tape is attached to a divider of the divided recessed second heel lift second surface.
 5. The first heel lift of claim 1, wherein a rear portion of the first heel lift is about 3 mm.
 6. The heel lift assembly of claim 1, wherein the first heel lift is an insole.
 7. The heel lift assembly of claim 1, further comprising a third heel lift, wherein the third heel lift has a third heel lift series of protrusion connection points on a third heel lift first surface and a divided recessed third heel lift second surface on an opposite side of the third heel lift from the third heel lift first surface; and wherein the series of protrusion connection points fit securely in the divided recessed second heel lift second surface.
 8. The heel lift assembly of claim 7, wherein a piece of hook tape is attached to a divider of the divided recessed third heel lift second surface.
 9. The heel lift assembly of claim 1, wherein the first heel lift has less height than subsequent heel lifts.
 10. The heel lift assembly of claim 1, wherein a slope of the heel lift assembly is no more than about 5.5 degrees.
 11. The heel lift assembly of claim 1, wherein a slope of the heel lift assembly is between about 0.5 and 5.36 degrees.
 12. The heel lift assembly of claim 1, wherein the heel lift assembly is placed beneath an insole of a shoe.
 13. A method for treating leg length asymmetry compensation comprising: (a) determining a height difference in leg lengths of an individual; (b) providing a heel lift assembly having a plurality of heel lifts, wherein the bottom of each heel lift has a divided recessed surface to connect with a plurality of protrusion connection points on a top surface of the heel lift below; (c) adjusting the number of heel lifts in the heel lift assembly to the height difference in the leg length of the individual; (d) inserting the heel lift assembly below an insole of a shoe so that a heel area is raised to the height difference determined in the leg lengths of the individual; and (e) positioning the individual's foot in the shoe containing the heel lift assembly such that when the individual is wearing the shoe, the leg length of a right leg and a left leg is the same.
 14. The method of claim 13, wherein an uppermost heel lift is softer than heel lifts below.
 15. The method of claim 13, wherein an uppermost heel lift is more compressible than heel lifts below.
 16. The method of claim 13, wherein a slope of the insole with the heel lift assembly is less than about 5.5 degrees.
 17. The method of claim 13, wherein the difference in the leg lengths is a functional inequality.
 18. The method of claim 13, wherein the difference in the leg lengths is an actual inequality.
 19. The method of claim 13, wherein the shoe is a sandal.
 20. The method of claim 13, wherein the leg length inequality compensation is coronal pelvic tile. 